I've submitted a Forbes article a couple of days before the IPO - http://news.ycombinator.com/item?id=4396500

Basically, if you bought a company with a P/E of 90 and decreasing revenue (it had dropped 6% in the quarter) then you shouldn't be playing with other people's money. Everyone knew it was a massive risk.

According to Google Finance, 14% of FB's outstanding shares are institutionally owned. I think the vast majority of the pension funds got the message.

You are right, if they had not over excitedly hyped themselves as a £100 billion company, this expectations won't be there. I believe they will do well to downgrade those expectations to that of a $5 - 20 billion company in the short term. In the near future (10 years), we never can tell as they could end up a $100 billion company. For now they won't be able to live keep up with the earning expectations of a $100 billion company.

The people complaining here are often the same people who BOUGHT the shares at the ridiculous IPO valuation. For a few hours, the market average seemed to think the IPO prices was too low. MZ didn't force anyone to buy shares at this price.